fiza Posted May 23, 2017 Posted May 23, 2017 We have had IP phones running on the same VLAN as the computers for about a year with no issues. Its a small school with around 40 phones and 70 computers. Recently users are complaining that when they make or receive a call parts of the conversation get lost and they have to ask the other end to repeat themselves. i want to use wireshark to see what is going on but I have never used it before and have no idea where to start. Can anyone help?
PotNoodleTech Posted May 23, 2017 Posted May 23, 2017 I would strongly advise running the phones on a separate VLAN. I don't think you're gonna get anywhere fast if you continue to run the phones on the computer VLAN as that will be full of broadcast traffic and other associated nasties. ON it's own VLAN the phones should be quiet and clear.
FN-GM Posted May 23, 2017 Posted May 23, 2017 UDP can be sensitive to broadcast traffic. If you VLAN them off there is a good chance it will sort the issue out.
mavhc Posted May 23, 2017 Posted May 23, 2017 (edited) Run wireshark to monitor your broadcast traffic, check it's not too high. https://community.spiceworks.com/topic/334348-using-wireshark-to-analyze-for-broadcast-storm?page=1#entry-4392560 Casper 9 Free can also view broadcast packets quite easily Are they all wired clients, or wireless too? Edited May 23, 2017 by mavhc
fiza Posted May 23, 2017 Author Posted May 23, 2017 I would strongly advise running the phones on a separate VLAN. I don't think you're gonna get anywhere fast if you continue to run the phones on the computer VLAN as that will be full of broadcast traffic and other associated nasties. ON it's own VLAN the phones should be quiet and clear. Yes I know but that can't happen in the short term. As I said its not been an issue for the last year since the phones were added. Run wireshark to monitor your broadcast traffic, check it's not too high. https://community.spiceworks.com/topic/334348-using-wireshark-to-analyze-for-broadcast-storm?page=1#entry-4392560 Casper 9 Free can also view broadcast packets quite easily Are they all wired clients, or wireless too? Majority wired. There are a few wireless clients. The school have recently added a handful of Wiley Fox mobiles for students to use Apps on. Could these be causing issues?
Willott Posted May 23, 2017 Posted May 23, 2017 I'm assuming this is occuring on internal as well as external calls (basic question, but not mentioned in OP)?
mavhc Posted May 23, 2017 Posted May 23, 2017 I'd run wireshark, filtered to just broadcast traffic on wired computer a, then create a phone call between wired computer b and c, send music via voip to a speaker and leave it running, then why you hear a problem, check the log on computer a. then do the same from computer b to wireless computer d
fiza Posted May 23, 2017 Author Posted May 23, 2017 I'm assuming this is occuring on internal as well as external calls (basic question, but not mentioned in OP)? Yes sorry - They only mentioned incoming and outgoing calls. I will check with the school about internal calls.
Willott Posted May 23, 2017 Posted May 23, 2017 If internal calls are fine, how are their external lines delivered? What's their WAN/internet connectivity like?
nicholab Posted May 23, 2017 Posted May 23, 2017 This is like that no QOS is set up we had this the voice mail server was on the VLAN with no quality of service.
Davit2005 Posted May 23, 2017 Posted May 23, 2017 Could be a dirty device broadcasting, maybe a HP Printer or Bonjour. Should always segregate voice traffic from anything else. 1
fiza Posted May 23, 2017 Author Posted May 23, 2017 If internal calls are fine, how are their external lines delivered? What's their WAN/internet connectivity like? I'm waiting for a response about internal calls. The phone provider/ISP has checked their end and say no issues found.
IrritableTech Posted May 23, 2017 Posted May 23, 2017 I'm waiting for a response about internal calls. The phone provider/ISP has checked their end and say no issues found. I think @Davit2005 makes a good shout - any new devices on the network recently that might be causing lots of broadcast? Otherwise if you can, nip onto your core switch and enable a mirror port. Then connect a laptop to it and run wireshark. You'll soon find out which device is broadcasting more than it should. If you do get the time though - separate VLANs is the way to go in future. 2
Davit2005 Posted May 23, 2017 Posted May 23, 2017 I think @Davit2005 makes a good shout - any new devices on the network recently that might be causing lots of broadcast? Otherwise if you can, nip onto your core switch and enable a mirror port. Then connect a laptop to it and run wireshark. You'll soon find out which device is broadcasting more than it should. If you do get the time though - separate VLANs is the way to go in future. We had a tech put printers on the same vlan where phones were and we immediately saw issues, noise mostly, HP 2055dn were mostly culprit although other printers could be prone.
MatthewL Posted May 23, 2017 Posted May 23, 2017 Just a note re internal calls, is the VOIP in house or external to you? I would be looking at VLANing them off and putting a QOS on if it is hosting externally.
gh5000 Posted May 23, 2017 Posted May 23, 2017 Had this exact same issue recently with out system (inherited no vlans also). Anyway after digging around NetSupportDNA was sending out a broadcast every 15 minutes looking for new computers etc. Turned off autodiscovery and it's been fine since. Just incase you use NetSupport. 1
mjk Posted May 23, 2017 Posted May 23, 2017 Yes I know but that can't happen in the short term. As I said its not been an issue for the last year since the phones were added. Why can't it happen in the short term? How long is it going to take? Configure a scope, configure your switches. 40 phones and 70 computers you should have that done inside an hour.
fiza Posted May 23, 2017 Author Posted May 23, 2017 Had this exact same issue recently with out system (inherited no vlans also). Anyway after digging around NetSupportDNA was sending out a broadcast every 15 minutes looking for new computers etc. Turned off autodiscovery and it's been fine since. Just incase you use NetSupport. Funny you should say that!! We have just installed DNA in the last few weeks. How do you turn off auto discovery please?
IrritableTech Posted May 23, 2017 Posted May 23, 2017 Funny you should say that!! We have just installed DNA in the last few weeks. How do you turn off auto discovery please? Right click on the Highest level in the PCs Tree on the left and click Settings. in the right hand column you'll find Auto Discovery and you can turn it off in there.
gh5000 Posted May 23, 2017 Posted May 23, 2017 Funny you should say that!! We have just installed DNA in the last few weeks. How do you turn off auto discovery please? In DNA be on the Home Screen with the list of PCs. Right click your school name, Settings, Auto Discovery, Untick enabled then save and propagate to all machines. 1
gh5000 Posted May 23, 2017 Posted May 23, 2017 (edited) In DNA be on the Home Screen with the list of PCs. Right click your school name, Settings, Auto Discovery, Untick enabled then save and propagate to all machines. My case ref was PR129758 if you want to quote it to NetSupport. They gave me a patch which I haven't installed yet. I've just got auto discovery turned off and install the client via SCCM. Out of curiosity what version are you running? I started seeing the issue on 4.40.3 Edited May 23, 2017 by gh5000 1
fiza Posted May 23, 2017 Author Posted May 23, 2017 Why can't it happen in the short term? How long is it going to take? Configure a scope, configure your switches. 40 phones and 70 computers you should have that done inside an hour. Easier said than done when I have zero knowledge of how to configure VLANs. - - - Updated - - - My case ref was PR129758 if you want to quote it to NetSupport. They gave me a patch which I haven't installed yet. I've just got auto discovery turned off and install the client via SCCM. Out of curiosity what version are you running? I started seeing the issue on 4.40.3 Yes we have 4.40.3.708 which is still in trial version I havent added the licence details yet.
gh5000 Posted May 23, 2017 Posted May 23, 2017 (edited) - - - Updated - - - Yes we have 4.40.3.708 which is still in trial version I havent added the licence details yet. Well turn off autodiscovery and watch as your network returns to normal, your phone stops ringing and helpdesk stops adding tickets. Was a nightmare until I tracked it down. @Al_NetSupport has this issue been fixed in 4.40.4 or 4.5? (your ref PR129758) Apart from that and bringing our network to a halt with a Sophos incompatibility when we first installed it's been a really useful tool if your still evaluating. Edited May 23, 2017 by gh5000
fiza Posted May 23, 2017 Author Posted May 23, 2017 Well turn off autodiscovery and watch as your network returns to normal, your phone stops ringing and helpdesk stops adding tickets. Was a nightmare until I tracked it down. @Al_NetSupport has this issue been fixed in 4.40.4 or 4.5? (your ref PR129758) Apart from that and bringing our network to a halt with a Sophos incompatibility when we first installed it's been a really useful tool if your still evaluating. Yeh we have had it in our main school for a while now but we don't have IP phones. We only recently installed it in the Primary as a trial version and now they have purchased it.
Al_NetSupport Posted May 23, 2017 Posted May 23, 2017 Well turn off autodiscovery and watch as your network returns to normal, your phone stops ringing and helpdesk stops adding tickets. Was a nightmare until I tracked it down. @Al_NetSupport has this issue been fixed in 4.40.4 or 4.5? (your ref PR129758) Apart from that and bringing our network to a halt with a Sophos incompatibility when we first installed it's been a really useful tool if your still evaluating. Hi @ghanel thanks for the post and looping me in. Always happy to answer your questions and be as open as i can. Yes we addressed an issue where if auto-discovery was set on a large network at too narrow a frequency it could interfere with a VOIP system. It was reported and fixed shortly after and was released in version 4.40.0004. This was only reported on a couple of sites and would not be relevant to anyone evaluating with the latest versions. You also mentioned Sophos, and this relates to the way Sophos install their solution on Windows 7 using an LSP. It does not play well if any subsequent solution using an LSP is installed, or subsequently modified. NetSupport DNA uses an LSP for Windows 7 and earlier platforms ( we use a webfiler on Win 8 and later), and we have added a detection rule for Sophos on our install to avoid any future clash. This was also included in an earlier update. Truth is we do find clashes every now and then with existing software or systems, we apologise and we ensure a solution is made available pronto. Hope that clarifies, but feel free to PM me if you have any more specific questions and I can find out answers. Al.
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